cc: Setup API to release OutputSurface from LTHClient.

cc/trees/single_thread_proxy.cc

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/trees/single_thread_proxy.h"
 
 #include "base/auto_reset.h"
 #include "base/profiler/scoped_tracker.h"
 #include "base/trace_event/trace_event.h"
 #include "cc/debug/benchmark_instrumentation.h"
@@ skipping 131 matching lines @@
 void SingleThreadProxy::RequestNewOutputSurface() {
   DCHECK(Proxy::IsMainThread());
   DCHECK(layer_tree_host_->output_surface_lost());
   output_surface_creation_callback_.Cancel();
   if (output_surface_creation_requested_)
     return;
   output_surface_creation_requested_ = true;
   layer_tree_host_->RequestNewOutputSurface();
 }
 
+scoped_ptr<OutputSurface> SingleThreadProxy::ReleaseOutputSurface() {
+  if (scheduler_on_impl_thread_)
+    scheduler_on_impl_thread_->DidLoseOutputSurface();

[danakj, 2015/09/17 18:43:55]

Can you DCHECK that LTH knows the OS is lost, and comment on that saying that we
don't need to call LTH::DidLoseOutputSurface since it already knows?

+  return layer_tree_host_impl_->ReleaseOutputSurface();
+}
+
 void SingleThreadProxy::SetOutputSurface(
     scoped_ptr<OutputSurface> output_surface) {
   DCHECK(Proxy::IsMainThread());
   DCHECK(layer_tree_host_->output_surface_lost());
   DCHECK(output_surface_creation_requested_);
   renderer_capabilities_for_main_thread_ = RendererCapabilities();
 
   bool success;
   {
     DebugScopedSetMainThreadBlocked main_thread_blocked(this);
@@ skipping 741 matching lines @@
       << "DidFinishImplFrame called while not inside an impl frame!";
   inside_impl_frame_ = false;
 #endif
 }
 
 void SingleThreadProxy::SendBeginFramesToChildren(const BeginFrameArgs& args) {
   layer_tree_host_->SendBeginFramesToChildren(args);
 }
 
 }  // namespace cc